principles 2: pathology Flashcards
what is metaplasia?
reversible change in which one adult cell type is replaced by another cell type
what is dysplasia?
abnormal pattern of growth in which some of the cellular & architectural eatures of malignancy are present
- pre-invasive stage with intact basement membrane
what are the features of tissue dysplasia?
- loss of architectural orientation
- loss in uniformity of individual cells
- hyperchromatic + enlarged nuclei
- abundant, abnormal mitosis in places not usually found
where in the body is dysplasia commonly found?
- cervix (HPV)
- bronchus (smoking)
- colon (UC)
- larynx (smoking)
- stomach (pernicious anaemia)
- oesophagus (acid reflux)
what is the difference between low & high grade dysplasia?
high grade indicates higher risk of invasive cancer & reversibility is decreased
what is neoplasia?
an abnormal, autonomous proliferatoin of cells unresponsive to normal growth mechanisms
what are some features of benign tumours?
- do not invade & metastasise
- are encapsulated
- are usually well differentiated
- are slow growing
- have normal mitosis patterns
when can benign tumours be fatal?
if they:
- are in a dangerous place eg meninges, pituitary
- secrete something dangerous eg insulinoma
- get infected eg bladder
- bleed eg stomach
- rupture eg liver adenoma
- tort (twist) eg ovarian cyst
what are some features of malignant tumours?
- invade surrounding tissues
- spread to other sites
- no capsule
- well to poorly differentiated - rapidly growing
- mitose abnormally
what is a metastasis?
discontinuous growing colony of tumour cells at some distance from primary cancer
what does metastasis depend on?
lymphatic & vascular drainage of primary site
what is papilloma?
benign tumour of SURFACE EPITHELIUM
eg skin, bladder
what is an adenoma?
benign tumour of GLANDULAR EPITHELIUM
eg stomach, thyroid, colon, kidney, pituitary, pancreas
what is a carcinoma?
malignant tumour derived from EPITHELIUM
eg squamous cell, adenocarcinoma, transitional cell, basal cell
what is an osteoma?
benign tumour of SOFT TISSUE
what is a sarcoma?
malignant tumour derived from CONNECTIVE TISSUE (mesenchymal cells)
what are the types of sarcoma?
fat: liposarcoma
bone: osteosarcoma
cartilage: chondrosarcoma
striated muscle: rhabdomyosarcoma
smooth muscle: leiomyosarcoma
nerve sheath: malignant peripheral nerve sheath tumour
what is leukaemia?
malignant tumour of BONE MARROW DERIVED CELLS which circulate in blood
what is lymphoma?
malignant tumour of LYMPHOCYTES (usually in lymph nodes)
what is a teratoma?
tumour derived from GERM CELLS
- have the potential to develop into tumours of all three germ cell layers (ectoderm, mesoderm, endoderm)
what is the difference between male & female teratomas?
in male all are malignant but in females most are benign
what is hamartoma?
localised overgrowth of cells & tissues NATIVE TO ORGAN
- cells are mature but architecturally abnormal
- eg bile duct, bronchial
